Urban Planning 101 – Mixed Use


Here at Postgreen we spend a lot of time fussing over our buildings. We go back and forth with our architects over floor plans, deliberate over finishes and constantly look for supplies of sustainably harvested or recycled “green” building products. We figure, if we’re going to put our name on it we want it to be something we can be proud of. But if you’re developing a piece of land in a city, or in many cases multiple pieces of land, issues of urban planning are some of the first considerations driving the design process. Whether its fighting with the zoning department for usage variances or trying to squeeze a few more inches in allowable building height to fit that green roof, we end up first thinking about our projects at an urban scale. Since no one at Postgreen has any official title in urban planning it’s something we’ve had to learn on our own.

To keep you all informed and to give us a solid reason to keep reading the books we love but really don’t have for we’ve decided to start a series of blog posts. Let’s call it “Urban Planning 101″. Hopefully you find some of these ideas as interesting as we do and will keep an eye out for some of them popping up in our projects.

There is no better place to start urban planning 101 than with Jane Jacobs, the activist/journalist who opposed the great urban planner Robert Moses. Jacob’s opposed Moses’ plans for more highways, parking lots and high-rise residential buildings with more walkable streets, greater building density and fewer cars. She wanted to make the city pedestrian friendly because above all else, cities are meant for people.


Jane Jacobs Vs. Robert Moses

So how do you make a city pedestrian friendly? Well first you need people to feel safe walking down the streets. The best way to do this according to Jacobs’ is to “put eyes on the street” and of course behind those eyes are people. Although a city is full of strangers it is those strangers occupying the streets around the clock that will make it feel safe. This is where “mixed use” becomes important.

If a certain neighborhood is filled with residential building after residential building, (that would be a single use neighborhood in urban planning lingo) people will be walking down the streets on their way to and from work and maybe after work to go out to eat. That’s people on the street from about 6-9 in the morning and then 5-8 in the evening but during the mid day and night there is no reason for anyone to be on that street. Now put a commercial store on that block and suddenly shoppers are walking down the street throughout the day. What’s even better is that shopkeepers typically hate dirty sidewalks, broken windows and holdups. The more inviting their street feels the more business they will get so it is in their best interest to maintain their block. Once you’ve got that midday use, add a bar or restaurant and you’ve got people stumbling around until 2 or 3 in the morning, and yes, drunk eyes are still better than no eyes.

Mixing up building uses (mixed use neighborhood) is a great way to get people to use the streets. It puts them to work as unofficial policers of street activity. They don’t get paid and there’s no corruption, what could be better?

Single Use - A little sparse people-wise

Mixed Use - Just look at all the unofficial police officers








Now this whole safe street thing is about to snowball. Once a street becomes more crowded with people walking around others treat it as kind of a spectacle and will come out just to sit and watch. Sure I imagine most of these watchers are retiree’s with nothing better to do, but their eyes work too… well sort of. I’m sure mothers walk the streets with their kids during the day also, just to get them out of the house. The bottom line is, once a street becomes safer and more exciting to walk down it begins to solidify itself as a safe street.

When Robert Moses and Jane Jacobs were still duking it out, a lot of urban planners were under the impression that cities had to be more organized with building uses all grouped together; residences in one area, shops in another, arts and culture in another. But really cities have to be messy. Every neighborhood needs a little bit of each use. The activity on one street should bleed into the next and boundaries should be amorphous.

Typically neighborhood zoning is set up for at least a minimal amount of mixing. In many heavily zoned residential neighborhoods the corner lots are zoned for commercial/mixed use. Corner lots are great for commercial space because the owner gets two street fronts to advertise his business and two streets means twice as many passerby’s. Although just because these lots are often zoned for commercial/mixed use they don’t always attract a commercial interest and thus lie vacant or are taken up as a residence. In some of our more recent projects, Folsom Powerhouse and ReNewbold we’ve tried to bring back the commercial corner. Each property is in a heavily residential area and could use a little more mixing. At ReNewbold we’re aiming for a retail tenant which would get people walking down the street during the day. At Folsom Powerhouse we’re creating an office space for a small business to get set up. Although a small office isn’t necessarily a big draw for pedestrians it can bring in workers and clients from out of town or other parts of the city who may use public transportation to reach the office or just spend money on the occasional lunch nearby. Things like this help distribute the wealth of a city and strengthen other local businesses.

Creating mixed use neighborhoods is the crux of urban planning. It’s something we’d love to do more of, despite the fact that it often means more zoning variances filed with the city of Philadelphia. Ugh.  But with its power to change the city for the better how could we not do it. Be on the lookout for some Postgreen work on Frankford Ave utilizing the mixed use concept. This is a commercial corridor we love, especially since its in our neighborhood. Naturally we want to see it full of people buying clothes, eating at restaurants, going grocery shopping, getting their car fixed, grabbing a drink, seeing a show, lounging in the park and being able to do all this just  short walk from their home.


  1. Mike Goldstein says:

    Love what you guys are doing! Keep up the hard work.

  2. Great to see some discussion on urban planning. I imagine Jane Jacobs was seen by many as a troglodyte back when The Death and Life of Great American Cities was written. After the suburban experiment many are recognizing the importance of this book. It is required reading for anyone developing infill projects (and should be for all employees of substantial municipal planning departments).

    In my opinion creating healthy mixed use environments can be challenging in areas that really don’t have adequate population density. The first image in the post shows two story row homes, I assume in Philadelphia. The second shows a much more vertically dense street that is better able to support multiple uses. I think Postgreen’s effort to incorporate some non-residential uses in an effort to activate the street corners is the appropriate approach for the medium density areas in which it builds. Another thought would be to incorporate some street level office space in “live/work” units along the remainder of the street, a la Bob’s Burgers (sorry, this is the best example I could find as I don’t believe Mr. Hooper actually lived above his store). On larger projects a few three story units with two living levels above a potential office/retail space at sidewalk level could start to supplement the corner commercial spaces.

    Again, it is great to see these kind of spaces in the projects. It means that real communities are being to be recreated.

  3. brianledder says:

    Thanks Matt. I like that you’re thinking about density as it relates to commercial space. It think you’re right that you do need a high enough density for commercial space to work. It makes sense because generally commercial space, especially corner commercial space is there to serve the local population. I think office space and “live work” units are a little bit different. Office space inst necessarily there to serve the local population. It does bring in users from outside during the day which we love, but at night those users leave and unless there are enough restaurants and bars to bring in evening/night users and a high enough density of residents to support the restaurants I think the office space can be risky.

    With that being said, office space is exactly what were planning at Folsom Powerhouse. The Fairmount night life is pretty well established and the neighborhood, although mostly 3 story row homes, has fewer and fewer vacant lots everyday. I think its reaching the point where office space becomes a good urban choice. Although for now, we’re keeping it to just one unit.

  4. Peg Laramee says:

    Another kind of mixing could occur if some of the residential units are for individuals committed to “aging in place”, that is to say, the place that they love, the urban neighborhood where everything’s going on that they’ve been interested in for years. If these guys are retired, they often are moving around the ‘hood during the day, doing what they do, meeting up with whomever. These are more eyes on the ground…but it could be that they need a different kind of home, a barrier-free one–so anyone can visit them. Perhaps an affordable home, but not necessarily a subsidized or low-income one. They may prefer to rent…another zoning hurdle? Is home ownership ALWAYS the American dream? Well, you maybe can’t “please everyone”, but I sure wouldn’t be pleased to think I should leave the city, invest in a very UNmixed “community” out in the middle of nowhere…the proverbial “retirement community”. It’s all very well, but not for us.

  5. […] Use” comes into play. If you’re a loyal follower of our blog you already know from our first Urban Planning 101 post that “Mixed use” is the backbone of a healthy neighborhood. But in case you forgot […]

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